Hi,
really it's my fault, because I haven't released yet a good starting guide for ReDJ. I'm working on it and it will be released in a few days. At the moment only for Tag Meta the tutorial is available but the "principle" between ReDJ "from URL" and Tag Meta "uri" is exactly the same (so please read it). The ReDJ "to url", instead, must be absolute and {siteurl} macro is also supported.
So, let's see your examples.
I am trying to redirect the URL
testsite.novustoday.com/index.php?option=com_content&view=article&id=264:first-solar-and-nrg-energy-open-largest-solar-pv-power-plant-in-california&catid=59:headlines
to the URL
testsite.novustoday.com/index.php?option=com_content&view=article&id=263:first-solar-and-nrg-energy-open-largest-solar-pv-power-plant-in-california&catid=37:business-news&Itemid=203
Create a new ReDJ item as follow:
From URL: /index.php\?option=com_content&view=article&id=264:first-solar-and-nrg-energy-open-largest-solar-pv-power-plant-in-california&catid=59:headlines
To URL: http://{siteurl}/index.php?option=com_content&view=article&id=263:first-solar-and-nrg-energy-open-largest-solar-pv-power-plant-in-california&catid=37:business-news&Itemid=203
Note that the question mark in the "from url" is escaped (\?). It should work (remember to activate plugin "System - ReDJ").
Let me know, if there are other problems.
Regards,
Luigi